Arts and Industries Building Revitalization Winner of 2016 Outstanding in Structural Engineering Excellence Award by SEAMW
|Client||Smith Group, JJR|
The Arts and Industries Building (AIB), a National Historic Landmark designed by Cluss and Schulze Architects in 1879, was the first structure built to house the U.S. National Museum. It is one of the finest examples of historic exposition architecture in the country. Its 19th century state of the art fire proof masonry walls and light weight iron trusses and purlins support 46 different roof areas. The interior was so spectacular that it hosted President Garfield’s Inaugural Ball when it opened in 1881.
The AIB has a a central rotunda 100 feet tall and four halls and courts 53 feet tall which are surrounded by eight ranges. In the last 50 years, some of these high areas were filled in with additional floors but otherwise very few changes were made. In 2009, it was the Smithsonian Institution’s desire to repair the exterior envelope, remove the added floors, and restore the AIB back to its original layout. In addition, the entire building was to be upgraded to meet current code requirements for snow, wind, seismic, blast and progressive collapse.
The historic roof had performed relatively well for 130 years. However, adding energy efficient roof insulation would delay the melting of snow, causing higher drifts in the many valleys and crickets on this complex roof arrangement. Current code snow load values were judged inaccurate and too conservative and would have required significant strengthening of the roof structure. Therefore, a computerized snow and wind model was generated to accurately reflect snow accumulation unique to each area of the roof. Even though the building is symmetrical, the snow loading is not.
The combination of accurate loading, testing of wrought-iron members, use of high strength steel and sophisticated modeling and analyses allowed many historic trusses to remain, some to be nominally strengthened and a few to be replaced with similar sized members.
The exterior walls were originally designed with a cavity to act as cooling mechanism. However these separate wythes of masonry and its uncertain properties required careful probing and in-situ testing. This information was used to analyze the tall unreinforced brick masonry piers and walls for wind, seismic, progressive collapse and blast requirements.
Out-of-plane seismic deficiencies were resolved by connecting each roof diaphragm to the historic masonry. The in-plane seismic loads and drifting problems were resolved by tying the towers to the hall walls and then to the rotunda. Blast loads were considered in the roof modifications as well as in the new windows and their connections to the masonry.
Throughout the design phase, the Smithsonian and the design team needed to maintain a proper balance between economic feasibility and historic preservation without compromising structural safety.
|Client||Smith Group, JJR|